1. Field of the Invention
The present invention relates to electromotive machines and particularly to electromotive machines including electric motors, such as an induction motor, a synchronous motor, etc., as well as to a method for manufacturing an electromotive machine have insulated coils.
2. Description of Related Art
In the construction of an induction motor or a synchronous motor, a stator and a rotor are used. The stator is constructed by inserting a large number of coils into respective slots which are provided on a core. As a method for manufacturing such the stator, a so-called inserter method already has been known and applied, particularly in a small-sized electric motor, as is disclosed in Japanese Laid-Open Patent No. 53-100402 (1978), in which a coil wound previously in a predetermined shape is set in a coil guide by xe2x80x9ca bladexe2x80x9d and is pushed into the slot of the core by a jig for stuffing. An electric insulation between the coils and the core in that structure is obtained by applying a method, in which, as shown in FIG. 8, in addition to the insulator coating of a wire, a slot insulating paper 62 is previously disposed on an interior surface of the slot 61 of the core and then the coil 63 is inserted therein.
In a field of a large-sized electric motor, the coil insertion is worked out by hand, i.e., inserting a coil 64 which is shaped previously into a slot of a core. An electric insulation between the coils and the core in that structure is obtained, as is shown in FIGS. 9 (a) and (b), by taping an electric insulator 65 and 66 around the coil 64.
In a small-sized electric motor, since the slot insulating paper is provided in the slot previously, a gap or an aperture is formed between the slot insulating paper and the core, as well as a certain degree of the gap or aperture must be formed among the wires forming the coils so as to insert the coils onto the slot insulating paper provided in the slot. As a result of this, a space factor (i.e., a ratio of an electric conductor a space occupying within a slot in the cross section thereof) decreases.
In a large-sized electric motor, the coil is wound with the insulator not only once but also wound twice in a portion thereof in a previous step or process of the taping, therefore, the size of the coil fluctuates in a cross-section thereof. In a relationship between the slot size of the core, the portion which is largest in the size of the cross-section must be less than the slot size, and other portions thereof are smaller than that. Therefore, the space factor of the slot is decreased. Further, the fluctuation in the size of the cross-section also brings a problem of causing difficulty in the insertion of the coil into the slot.
An object of the present invention is solve the drawbacks mentioned above and to provide a method for manufacturing an insulated coil, by which the space factor of the slot can be improved, with high accuracy in cross-sectional size of a coil portion to be inserted into the slot, as well as, improving assembly of the coil inserted into the slot.
Another object of the present invention is to provide a method for manufacturing an insulated coil, with which small-sizing of the rotating electromotive machines, including electric motors can be realized by improving the space factor and efficiency thereof.
Moreover, another object of the present invention is to provide rotating electromotive machines including electric motors, with which small-sizing can be realized by improving the space factor and efficiency thereof.
For achieving the objects mentioned above, in accordance with the present invention, there is disclosed a method for manufacturing an insulated coil comprising the steps of: an aligning and winding step for forming a coil by aligning and winding a wire which is coated with insulating material thereon; an insulator forming step for winding or coating an insulator around a portion of said coil to be inserted into a slot, which is formed in said aligning and winding step, laying an adhesive layer or agent therebetween; and a shaping step for shaping and fixing said wire and said insulator in the slot inserting portion as an unit, through melting by increasing the temperature thereof and thereafter cooling said adhesive layer or agent of said slot inserting portion, around which the insulator is wound or coated, laying the adhesive layer or agent therebetween in said insulator forming step, under a restrained condition using a metal mold for shaping.
Further, in accordance with the present invention, there is provided a method for manufacturing an insulated coil comprising, winding an insulator around a slot inserting portion of the coil after winding thereof, and shaping and fixing said wire and said insulator as an unit, through melting an outer periphery of the insulator coating of the wire or an adhesive layer on an interior surface of the insulator by increasing the temperature thereof and thereafter cooling it, keeping a restrained condition onto the slot inserting portion of the coil using a metal mold for shaping having an interior periphery size equal to the size of the finally finished coil.
Furthermore, in accordance with the present invention, there is provided method for manufacturing an insulated coil comprising the steps of: an aligning and winding step for forming a coil by aligning and winding a wire which is coated with insulating material thereon; an insulator forming step for winding or coating an insulator around a portion of said coil to be inserted into a slot, which is formed in said aligning and winding step, in a condition of forming an adhesive layer or agent on an outer peripheral surface of insulating material coating which is coated on said wire; and a shaping step for shaping and fixing said wire and said insulator in the slot inserting portion as a unit, through melting by increasing the temperature thereof and thereafter cooling said adhesive layer or agent of said slot inserting portion, around which the insulator is wound or coated laying the adhesive layer or agent therebetween in said insulator forming step, under a restrained condition using a metal mold for shaping.
Moreover, in accordance with the present invention, there is provided a method for manufacturing an insulated coil comprising the steps of: an aligning and winding step for forming a coil by aligning and winding an insulator coated wire, on an outer surface of which is formed an adhesive layer or agent; an insulator forming step for winding or coating insulator around a portion of said coil to be inserted into a slot, which is formed in said aligning and winding step; and a shaping step for shaping and fixing said wire and said insulator in the slot inserting portion as an unit, through melting by increasing the temperature thereof and thereafter cooling said adhesive layer or agent of said slot inserting portion, around which the insulator is wound or coated, laying the adhesive layer or agent therebetween in said insulator forming step, under a restrained condition with using a metal mold for shaping.
Further, in accordance with the present invention, there is provided a method for manufacturing an insulated coil comprising the steps of: an aligning and winding step for forming a coil by aligning and winding a wire which is coated with insulating material thereon; an insulator forming step for winding or coating an insulator, on an interior surface of which is formed an adhesive layer or agent, around a portion of said coil to be inserted into a slot, which is formed in said aligning and winding step; and a shaping step for shaping and fixing said wire and said insulator in the slot inserting portion as a unit, through melting by increasing the temperature thereof and thereafter cooling said adhesive layer or agent of said slot inserting portion, around which the insulator is wound or coated laying the adhesive layer or agent therebetween in said insulator forming step, under a restrained condition using a metal mold for shaping.
Further, in accordance with the present invention, in a method for manufacturing the insulated coil mentioned above, the melting temperature of said adhesive layer or agent is lower the heat-resisting temperature of said insulator coating and of the insulator. Further, in the method for manufacturing the insulated coil mentioned above, the adhesive layer or agent is thermoplastic resin. Furthermore, in the method for manufacturing the insulated coil mentioned above, the insulator is made of aramid paper or of prepreg insulating sheet material.
Further, in accordance with the present invention, there is provided an electromotive machine comprising a slot, into which is inserted a slot inserting portion of an insulated coil manufactured by the method for manufacturing an insulated coil as mentioned above.
Further, in accordance with the present invention, there is provided a rotating electromotive machine comprising a stator core having a slot, into which is inserted the slot inserting portion of the insulated coil manufactured by the method for manufacturing an insulated coil as mentioned above.
Further, in accordance with the present invention, there is provided an electric motor comprising a stator core having a plurality slots, into which are inserted the slot inserting portions of insulated coils for U-phase, V-phase and W-phase, which are manufactured by the method for manufacturing an insulated coil as mentioned above.
In accordance with the above-mentioned construction, it is possible to enhance the accuracy in sizes of a cross-section of the coil including the insulator, and as a result it is also possible to increase the space factor of the slot of the stator, thereby realizing small-sizing of the rotating electromotive machines including electric motors, as well as improving the efficiency thereof.
Further, in accordance with the above construction, it is possible to enhance the accuracy in sizes of a cross-section of the coil including the insulator, and as a result, it is also possible to reduce the cost of the material, for example, by reducing amount of conductor used therein.
Further, in accordance with the above construction, since the electric motor constitutes a key part in a set product, it is possible to realize a smaller sized, lighter weight and lower priced product using the electric motor.